This is the base with micrometer for my Foucault tester. Louis Barendse of the SAAO Pretoria center gave this to me as the base of my tester. A real gentleman. The idea for this particular tester originated with Louis as well, and I am forever grateful to him. The bits on top was constructed from 25mm square and 25mm * 50mm rectangular tubing. The base is made out of 16mm MDF (supawood).
The main aim for this tester is to allow measurement to a fine tolerance, but more importantly, it must be repeatable to this tolerance.
The front board is made out of two copper clad pc boards, 80mm * 120mm. The front and back part was drilled with a 25mm hole saw for visual and later camera adaption. Above that, about 6mm away, is a 8mm hole for the illumination of the mirror. Behind this will be a microscope slide glass mirror at a 45o angle. The light source will enter from the side and could be a Maglight or fibre optic source. Above this is a high brightness 3mm green led, 45Mcd. This will be used for mirror alignment when the camera is mounted. Should be easier than running between the mirror and checking on the alignment
The front board was made like this for neatness and to hide wires and switches away. Distance between the boards are 14mm, maintained by metal standoffs and also used for mounting it to the baseboard. This also gives mounting space for the led and power switch as well as for the camera adaptor. This type of design allow me to keep stray light out of the camera as well. The picture unfortunately show the front board upside down, the smaller hole and led should be above the sighting hole. The board will be mounted like this and the final pictures should show it correctly. More pictures to follow as the building progresses.
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